Operations Statistics

Operations statistics tell us what kind of work our vector control technicians spent their time on in the past month. These numbers are useful for helping us make decisions about how to allocate resources or what programs to focus on.

Tables of acres treated refer to larger sources of standing water where mosquitoes may develop. Numbers of sourced treated include smaller residential sources of standing water, such as swimming pools and backyard containers.

This table shows the number of acres treated with larvicide during November and December. The number of acres treated during these months is low. Technicians are currently monitoring sources for mosquito larvae as they fill with water. The mosquito larvae are treated with larvicide when they reach the optimal growth stage. The number of acres treated will likely increase substantially in January, especially in marshes and impounds, depending on rainfall.

This table contains the number of each type of service request in November 2018 compared to the three-year average in November. The total number of service requests is somewhat below average, mainly because we have had fewer than typical mosquito-related requests. The number of yellowjacket and wasp service requests continued in a steep decline, shown in the graph, and will likely remain low until spring.

This table shows the number of acres treated with larvicide during September and October. The number of acres treated is drastically lower in October compared to September, largely from the marshes and impounds category. Helicopter treatments were not conducted during the month of October, which is a large part of summer acreage treated. Also, after a dry summer and mostly dry autumn thus far, there is less standing water throughout the county. Creeks and catch basins are continuously treated in summer.

This table contains the number of each type of service request in October 2018 compared to the three-year average in October. Total number of service requests are above average, mainly because of yellow jacket and wasp requests. Dead birds were also somewhat higher than average this October.

This table shows the number of acres treated with larvicide during August and September. The largest proportion of acres treated are in marshes and impounds, mainly from helicopter treatments. Creeks and catch basins are also continuously treated in summer. Although the acreage from creeks and catch basins is relatively small, they are numerous and can produce abundant adult mosquitoes without proactive inspections and larvicide treatments. Catch basin treatments will continue until heavy fall rains begin.

This table contains the number of each type of service request in September 2018 compared to the three-year average in September. Mosquito service requests continue to be well below average this year. This low number of mosquito requests reflects an effective catch basin treatment program and few media reports on mosquito-borne diseases this summer. Yellow jacket and wasp requests are the most abundant type of request in the summer and have been especially numerous this year, although the numbers are dropping from a peak in August.

This table contains the number of each type of service request in July and August 2018 compared to the three-year averages in July and August. Service requests are higher than average in most categories, with the notable exception of mosquito service requests in August 2018, which is well below average. This low number of mosquito requests is probably because of a cooler than typical August and an increasingly effective catch basin treatment program. Yellow jacket and wasp requests are the most abundant type of request in the summer and have been especially numerous this year.

This table shows the number of acres treated with larvicide during May and June. The largest proportion of acres treated are from creeks, which often have pockets of still water during the summer because of reduced water flow. The total number of acres treated in June is lower than May, mainly because of the reduction in acres of marshes and impounds. These wetland areas are mostly seasonal and have largely evaporated by June.

This table contains the number of each type of service request in June 2018 compared to the three-year average in June. Total service requests are higher this June than the three-year average, although the number of mosquito service requests is somewhat lower than average. Most of the increase is due to the spike in yellowjacket and wasp service requests, which are a seasonal problem.

This table shows the number of acres treated with larvicide during April and May. The largest proportion of acres treated are from marshes and impounds that continue to hold water, although that area was substantially decreased from April to May as the higher temperatures and decreased rainfall caused evaporation. Seasonal treatment in creeks began in May, which is reflected in the increase in acreage.

This table contains the number of each type of service request in May 2018 compared to the three-year average in May. The number of mosquito service requests in May 2018 was considerably lower than the three-year average. This is because there were a very high number of mosquito service requests in May 2017 (277) that resulted from Chironomid midges emerging from lagoons near the bay.

This table shows the number of acres treated with larvicide during March and April. The majority of acres treated are from marshes and impounds that continue to hold water. Seasonal catch basin treatments began in April, which is reflected in the increase in acreage.

This table contains the number of each type of service request in April 2018 compared to the three-year average in April. The number of mosquito service requests in April 2018 was considerably lower than the three-year average. This is because there were a very high number of mosquito service requests in April 2016 (225) amid news of Zika virus in South America.

This table shows the number of acres treated with larvicide during February and March. The majority of acreage in the winter is in marsh areas that have filled with rainwater. Mosquito control efforts in March were focused in marshes and impounds because it was an unusually rainy month. This work will prevent spring fly-offs of aggressive Aedes mosquitoes.

This table contains the number of each type of service request in March 2018 compared to the three-year average in March. The number of mosquito service requests in March 2018 was considerably lower than the three-year average. This is because a very high number of mosquito service requests in March 2017.

This table contains the number of each type of service request in January and February. Despite being a shorter month, February had more requests for service than January, which were mainly rodent-related.

Click on the graph to see the number of acres of each source type treated with larvicide during the month of February 2018.

This table shows the number of acres treated with larvicide during January and February. The majority of acreage in the winter is in marsh areas that have filled with rainwater. Unusually warm weather for a few weeks in February also caused breeding in catch basins, which were treated to prevent emergence of adult mosquitoes.